This invention relates generally to an improved hydraulic fuse unit to control flow of hydraulic fluid, and more particularly concerns an improved fuse unit provided with a metering valve to divide the flow into two parallel paths (metering flow and main through flow), which provides for a positive force margin across the fusing piston, and which minimizes the effects of contamination and operating atitude on fuse performance, and provides more consistent performance at low flow rates.
The fuse-assist metering piston may be devoid of seals, which allows for much more precise force margins throughout the entire range of operating flow and temperatures, and which results in more consistent volumetric capacity performance. The fuse assembly is mechanically a very simple, compact device, which requires only a minimum number of parts and is relatively easy to manufacture.
There is need for a fuse assembly having the above characteristics.